1. Field of the Invention
The present general inventive concept relates to an image reading apparatus, and, more particularly, to an image reading apparatus capable of reading both sides of a document and a method of controlling the same.
2. Description of the Related Art
An image reading apparatus reads image information recorded on a document and is mounted in a machine such as a scanner, a digital copier or a multi-function machine.
A method of reading both sides of a document in an image reading apparatus may be classified into two methods. There is a method of reading a first side of a transported document using a reading unit, changing a transport direction of the document via a document direction changing device, reversing the first side and a second side of the document via a duplex path, and reading the second side of the document (hereinafter, referred to as a “first method”, for convenience of description). Such a method is advantageous in that the both sides of the document can be read using one reading unit, but is disadvantageous in an amount of time required to read the both sides of the document.
There is a method of reading both sides of a document by mounting a first reading unit to read a first side of the document and a second reading unit to read a second side of the document to be opposed to each other (hereinafter, referred to as a “second method”, for convenience of description). Such a method is advantageous in that the both sides of the document can be simultaneously read without unnecessarily circulating the document and thus a both-side reading operation can be performed with a high speed. However, if any one of the first reading unit and the second reading unit is out of order, the both-side reading operation cannot be performed.
In order to solve such problems, Japanese Unexamined Patent Application Publication No. 2006-148294 relates to an image reading apparatus employing a combination of the first method and the second method. That is, the disclosed image reading apparatus includes two reading units (a first reading unit and a second reading unit) and a document reversing device (reverse transporting mechanism) such that the second method is applied without using the reverse transporting mechanism when the first reading unit and the second reading unit are normally operated and both sides of a document are read using a reading unit, which is normally operated, and the reverse transporting mechanism (the first method is applied) when any one of the first reading unit and the second reading unit is not normally operated.
However, in the conventional image reading apparatus, automatically determining an abnormal state in which at least one of the reading units is not normally operated is not accomplished. Accordingly, rapidly copying with a malfunction or failure of the apparatus is difficult for a user.